Really they are no longer a couple. Look at them holding hands and when they pose for pictures. Hands are not embraced and he does not have his hand on her in either posed picture. Yep - the fling is over. Sad but true

Zayn previewed the duet by posting a black and white pic of himself with Swifty on his Instagram -- but hey, she is bestiez with his girlfriend Gigi Hadid, so it wouldn't be unusual that they hang out... But collab?!